Consumers shopping for medicine on the Internet often are getting convenience, a good price and the cloak of privacy, but they may not be getting the real thing.

A burgeoning multibillion-dollar industry of counterfeit drugs — ranging from AIDS and cancer medications to antidepressants and sexual enhancers — is keeping regulators busy and leaving the public vulnerable.

These medicines can deliver too little, too much or none of the active ingredient — or the wrong one — and sometimes are adulterated with dangerous chemicals or contaminated by unsanitary manufacturing or storage conditions.

The FDA in recent years has confiscated millions of dollars worth of counterfeit and other illegal medicine. The agency, in partnership with international regulatory, customs and law enforcement agencies from 100 countries, shut down thousands of Internet pharmacies selling illegal drugs and seized about $10.5 million worth of pharmaceuticals during a weeklong crackdown on counterfeit and unapproved medications that began in late September.

"This is a drop in the bucket," said Ilisa Bernstein, director of the Office of Compliance in the FDA's Center for Drug Evaluation and Research. "We don't know how many websites are out there, but there are a lot more. We may have some impact on these 4,100 websites, but they can pop up days or weeks later using another URL and another way to deceive consumers."

It is illegal in the U.S. to sell medication without a valid prescription. All U.S. pharmacies, including those offering drugs online, must be licensed in the state where they are based or where they do business.

Foreign pharmacies can be licensed in the U.S. only if they follow all state and federal laws and distribute only FDA-approved products. No foreign pharmacy has met those requirements, said Carmen Catizone, executive director of the National Association of Boards of Pharmacy.

Yet consumers can access tens of thousands of illegal online pharmacies, many of them based overseas. Buying drugs under those circumstances is illegal.

"It's as if they are going to the corner and buying drugs from a drug dealer," said Dr. Bryan Liang, director of the San Diego Center for Patient Safety at the University of California at San Diego School of Medicine.

Bernstein said it's impossible to know exactly how many people have died or been hurt by taking counterfeit drugs, although there have been highly publicized cases in the U.S. and overseas.

"A lot of people don't want to admit that they bought these drugs or were harmed by them," said Liang, who is on the board of the Partnership for Safe Medicines. Some people never realize that the drug they took was not the real thing.

Keavin Blount, the son of a St. Louis-area woman who died of cancer, said his mother suffered through her final months after she bought a counterfeit from her local pharmacist and was injected with it by a nurse at the hospital where she was getting treatment.

The drug, Procrit, was prescribed to treat Maxine Blount's anemia after chemotherapy, and for a time it helped her regain her energy so she could participate in family activities, her son said. After several months, though, it seemed to stop working. Authorities later determined that the drug was a highly diluted counterfeit, but they were unable to find out where it came from.

"I felt that there were some days with my mother that were taken from us," Blount said.

Experts say some of the illegal operations are based in the U.S., often with an elaborate cast of participants who make, sell and distribute the drugs. Many of the drug ingredients come from overseas.

Eli Lilly and Co. is one of the drugmakers battling the problem.

"Sometimes one criminal operation will make the packaging with our name brand on it," said Jeannie Salo, director of Lilly's global anti-counterfeiting operations. "Another operation may make the ingredient, which is not the (real) thing. Another person might operate an Internet site."

The appearance of fakes can be convincing, she said. "In some cases, you'd never know unless you tested it," Salo said.

Last year, 532 different medicines were identified as having been counterfeited, said Tom Kubic, president of the Pharmaceutical Security Institute, a global network of security directors for pharmaceutical manufacturers.

The top three classes of drugs were genitourinary medicines — for erectile dysfunction and incontinence, for example — anti-infective drugs, including antibiotics and medicines to treat HIV-AIDS, and cardiovascular drugs, Kubic said.

Some illegal sellers, Kubic said, appear to have shifted their focus in recent years from patients to doctors and clinics.

Liang suspects some doctors look for cheap drugs on the Internet to use in their practices so they can bill private insurance or Medicare at the legal drug's higher reimbursement rate. But regardless of their intentions, they are taking a risk, he said.

Earlier this year, the FDA warned doctors and clinics, including at least 10 physicians in northern Illinois, that they may have bought fake Avastin, a cancer medicine administered intravenously.

One of the physicians, Dr. Fariborze Barhamand, who has a medical practice in Naperville, said through his attorney that he was unaware that the drug distributor was based overseas or that many of its products were not FDA-approved.

Jayme Matchinski, a partner at Hinshaw & Culbertson, a Chicago law firm, said her client was trying to help patients by shopping for lower-priced cancer drugs, which can be costly. Now he has been wrongly linked to an illegal operation, she said.

Doctors can be fooled too, she said.

Barhamand is upset, she said. "They had an account with that pharmacy but never received the drug or made any orders."

The FDA declined to comment on any of the doctors or clinics across the U.S. because of an ongoing investigation.

States hold the authority to license wholesalers and others involved in distributing drugs, which has resulted in a patchwork of state laws and regulations, said Vince Ventimiglia, an adviser to the Pharmaceutical Distribution Security Alliance, a coalition of more than 30 companies and trade groups in the pharmacy, logistics, distributing and manufacturing businesses.

"The patchwork creates opportunities for bad actors to shop around to weaker states," Ventimiglia said.

Experts say consumers should be reassured that medicines bought in drugstores such as Walgreens and CVS are safe. But some counterfeits have found their way into the legal supply chain.

Rick Roberts has spoken out about the problem for more than a decade, ever since he unwittingly injected a two-month supply of a fake drug that he bought from a CVS pharmacy. As part of his advocacy, he is scheduled to speak next month at a pharmaceutical supply-chain conference.

Roberts, an adjunct professor at the University of San Francisco, had been prescribed human growth hormone to treat his AIDS wasting syndrome. After giving himself an injection one day, he noticed a new stinging sensation that lingered.

When he checked with his pharmacist, he was told that the drug, Serostim, had been recalled because authorities suspected some doses were counterfeit.

For months he panicked about the possible impact on his health, which was unstable at the time, he said.

He found out later that for one month, he had injected only a sixth of the medicine he needed, and that another month's supply contained a hormone that women produce while pregnant.

Because he relies heavily on medications — he took about 10,000 pills last year — he examines the products more closely now.

"I'm very careful," he said. "Taking that many pills increases my chances of getting a counterfeit, if there is a counterfeit out there again. That's why (the incident) changed my life and how I approach all my medicine."

In 2005, CVS Caremark announced that it no longer would buy pharmaceuticals from wholesalers that trade in the secondary drug market, where there is more movement of product between multiple parties.

"Recently, this practice has faced increased scrutiny due to the rising concerns that wholesalers trading in the secondary market potentially provide an entry point for counterfeit or adulterated products to enter the legitimate pharmaceutical supply chain," a company statement said at the time. "CVS does not trade in the secondary drug market, and is now requiring its pharmaceutical wholesalers to meet this same high standard."

Mike DeAngelis, a company spokesman, said the change should help prevent future incidents.

"We believe this straightforward approach, combined with stricter licensing requirements for wholesale distributors, are the most effective ways to ensure the continued integrity and authenticity of the prescription drugs we dispense to our customers," DeAngelis said in an email.

Some industry experts say a national system of tracking medicines through the drug supply chain would make it easier to confirm legitimate products and identify suspicious ones. Efforts are under way to introduce federal legislation.

Other efforts are aimed at making it harder for criminal online pharmacies to operate. Liang has researched online pharmacies and found that the vast majority are illegal, he said.

"The best way to fix the problem is to make sales of prescription drugs online illegal, period, unless it is from a VIPPS-accredited pharmacy," he said.

VIPPS stands for Verified Internet Pharmacy Practice Sites, which was created by the National Association of Boards of Pharmacy to help distinguish legal pharmacies from illegal ones. Legal businesses are encouraged to display a VIPPS seal on their sites.

For now, it's buyer beware. If a deal seems too good to be true, it probably is, experts said. And anything suspicious should be reported immediately to authorities.

"It is important to make sure that consumers recognize that the U.S. drug supply chain is among the safest in the world, and we have laws and regulations in place to make sure we have that closed system," the FDA's Bernstein said. "But we still need to be vigilant."

A burgeoning industry of counterfeit medications sold online — ranging from AIDS and cancer drugs to antidepressants and sexual enhancers — is keeping regulators busy and leaving the public vulnerable.

Medicine bought from illegal Internet pharmacies might look real, but it could be counterfeit, contaminated, expired or otherwise unsafe. The FDA recently launched a campaign, BeSafeRX, to help consumers distinguish between legal and illegal online pharmacies.

How did we arrive at Tuesday's front page Tribune story on counterfeit drugs? The problem has been an ongoing issue, made worse in recent years by the proliferation of illegal pharmacies on the Internet.